کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4640029 1341258 2010 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Saving flops in LU based shift-and-invert strategy
موضوعات مرتبط
مهندسی و علوم پایه ریاضیات ریاضیات کاربردی
پیش نمایش صفحه اول مقاله
Saving flops in LU based shift-and-invert strategy
چکیده انگلیسی

The shift-and-invert method is very efficient in eigenvalue computations, in particular when interior eigenvalues are sought. This method involves solving linear systems of the form (A−σI)z=b(A−σI)z=b. The shift σσ is variable, hence when a direct method is used to solve the linear system, the LU factorization of (A−σI)(A−σI) needs to be computed for every shift change. We present two strategies that reduce the number of floating point operations performed in the LU factorization when the shift changes. Both methods perform first a preprocessing step that aims at eliminating parts of the matrix that are not affected by the diagonal change. This leads to about 43% and 50% flops savings respectively for the dense matrices.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Computational and Applied Mathematics - Volume 234, Issue 12, 15 October 2010, Pages 3216–3225
نویسندگان
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